It might make more sense to say that social media usage is just one large aspect of a child- like the presence or lack of presence of supportive adult figures, the presence or lack of presence of food security, good education, physical safety, etc.
I'm sure a teenager who runs exclusively in cutting or pro-anorexia social circles online is a much different teenager to one who primarily uses the internet to keep up to date on horse shows.
I think the "sh" and "ed" decode to "self-harm" and "eating disorder". The "tw" might be "trigger warning". Given that, the "you got one too?" might mean "you have an eating disorder too?", although it doesn't make grammatical sense as "you have a self-harm too?", although that could be interpreted as "you have a self-harm disorder too?". But I don't really know.
I'm sure a teenager who runs exclusively in cutting or pro-anorexia social circles online is a much different teenager to one who primarily uses the internet to keep up to date on horse shows.